In the effort to mitigate environmental pollution there is a growing global demand for sustainable materials in place of existing synthetic one. In this research work, stacked hybrid laminate composite were produced by combining alkali treated kenaf and bamboo natural fiber mats as reinforcement with a biopolymer polylactic acid as matrix through compression moulding technique. The current work intends to study the outcome of surface modification of natural fibers which modifies their performance characteristics. Here the overall characteristics: mechanical, tribological, thermal and physical properties were investigated for the fabricated sample and the assessments were made between the alkali treated and untreated fiber composites. The alkali treated samples exhibited an enhanced tensile strength of 44.83 %, flexural strength of 108.13 %, compressive strength of 86.21 % and peak degradation temperature compared to the untreated samples. In addition, the tribological characteristics of the treated hybrid composites were studied. The inherent hydrophilic characteristics of natural fiber which leads to water absorption is resisted by the chemical treatment and it is also confirmed by the Fourier Transform Infrared (FTIR) analysis.Morphological analysis of the fractured and worn composites was also conducted to examine the microstructural changes and interface bonding within the developed composites. The biodegradability of the developed composites under soil burial test showed that the untreated composites exhibited higher weight loss percentage compared to the treated samples. The experimental results reveal that the alkali chemical treatment significantly enhances the suitability and compatibility of kenaf and bamboo natural fibers in polymer composites for sustainable construction products like roofing sheets and door panels in rural terrain regions.

The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi (R), MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.